Search

Objectives: Evening blue light has been shown to suppress melatonin, which can negatively impact sleep quality. The impact of evening blue light blocking (BLB) interventions on sleep remains ambiguous due to lack of randomized control trials. The present study tests the hypothesis that BLB glasses improve subjective and objective sleep in a population of healthy adults., Design: Two-week, randomized, controlled, crossover design., Setting: At-home testing of individuals in Michigan and Montana., Participants: Twenty healthy adults (11 men, 9 women, age: 32 ± 12, body mass index: 28 ± 4 kg/m 2 )., Intervention: Following a 1-week run-in baseline (ie, no glasses), participants were randomized to 1-week of BLB or control (ie, clear lens) glasses. Upon finishing the 1-week intervention, participants crossed over to the opposite condition. In both conditions, glasses were worn for 7 consecutive days from 6 PM until bedtime., Measurements: Objective sleep parameters were obtained using wrist actigraphy. Subjective sleep measures were assessed using sleep diaries. Karolinska Sleep Diaries were used to assess perceived sleep quality., Results: BLB reduced subjective sleep onset (21 ± 28 vs 24 ± 21 minute, P = .033) and awakenings (1.6 ± 1.0 vs 2.2 ± 1.0 awakenings, P = .019) compared to the control condition. In contrast, objective measures of sleep were not significantly impacted. In fact, our primary outcome variable of total sleep time (TST) tended to be paradoxically shorter in the BLB condition for both subjective (468 ± 45 vs 480 ± 48 minute, P = .066) and objective (433 ± 40 vs 449 ± 39 minute, P = .075) TST., Conclusions: Blue light blocking glasses did not improve objective measures of sleep time or quality in healthy adults., (Copyright © 2021 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.)

Background/purpose: Despite the importance of sleep for athletic performance, there is a lack of normative sleep data and sex comparisons in collegiate athletes. The primary purpose of our study was to assess the prevalence of insufficient sleep in collegiate athletes, with a secondary aim to compare male and female athletes., Procedures: Participants included 121 collegiate athletes (65 men and 56 women) from six team sports and three individual sports. Subjective assessments of sleep included at-home sleep diary, Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and Insomnia Severity Index (ISI). Objective assessments of sleep included three consecutive off-season weekdays of wrist actigraphy to assess total sleep time (TST) and sleep efficiency (SE)., Main Findings: Actigraphy revealed that 94% of student-athletes received <8 hours of sleep/night, while 61% received <7 hours/night. Subjective assessments revealed that 35% had PSQI >5, 28% had ISI scores >7, and 19% had ESS scores >10. Objective TST was not different between sexes (6.7±0.1 vs. 6.7±0.1 hours, P = .99), but females demonstrated higher SE (87±1 vs. 82±1%, P < .01) and lower WASO (31±2 vs. 38±2 min, P = .02). Male athletes significantly overestimated TST (i.e., subjective minus objective TST) when compared to female athletes (Δ0.7±0.1 vs. Δ0.3±0.1 hours/night; P < .01). PSQI, ISI, and ESS were not different between sexes., Conclusions: The majority of male and female collegiate athletes received less than age-recommended levels of sleep, and 44% subjectively reported poor sleep quality, mild severity insomnia, and/or excessive daytime sleepiness. Sex differences were observed in male and female collegiate athletes., (Copyright © 2020 National Sleep Foundation. Published by Elsevier Inc. All rights reserved.)